Pinned mills for mixers of this kind have an annular stator, which is provided with cylindrical pins disposed parallel to one another. A disk-like rotor is arranged inside the stator, and cylindrical pins are arranged on the outer rotor circumference, parallel to the stator pins; a small gap is left between the pins so that the rotor pins travel past the stator pins. The rotor disk is driven at high speed by a motor located outside the mixer container. The rotor and stator are disposed spaced apart from the inside of the wall of the container. The mixing tools of the mixer may be embodied and arranged such that they slide at least partway through the space located between the rotor and stator, on the one hand, and the container wall on the other, so that the mixing tools will axially sweep through the greatest possible portion of the container. Accordingly, this provision is intended to prevent dead zones.
Pinned disk mills are used especially to distribute viscous, or pourable, materials in a defined manner, because a shear gradient is generated in the gap between the rotor pins and the stator pins.
The grinding effect in these pinned disk mills is not satisfactory, however. To improve the grinding performance, attempts have already been made to provide holes in the rotor disk. This merely increases the drive power of the pinned disk mill, without improving the grinding performance.